1. Field of the Invention
The present invention relates to an interface for a liquid crystal display (LCD) retract device for an aircraft.
2. Description of Related Art
To provide added comfort to the passengers of an aircraft, it was realized that the aircraft could be provided with television monitors that display movies and other programming during a flight. As a result, several years ago airlines started installing video entertainment systems in the form of ceiling mounted cathode ray tube (CRT) monitors. These CRT monitors were either stationary, manually deployable or electrically deployable. A system control unit (SCU) was typically used to send information signals such as video to one of the CRTs. More specifically, the SCU would receive a video signal from a VCR and send the video signal to one of the several CRTs on an aircraft. Additionally, the SCU would also provide power and control signals to the one CRT. By daisy chaining the other CRTs together with the one CRT receiving the signals from the SCU, the same signals from the SCU (video and power and control) could be provided to all of the CRTs. FIG. 1 shows an exemplary daisy chain arrangement wherein an SCU 10 sends video and power and control signals to an input of a first CRT 20A. An output of the first CRT 20A in turn outputs the video and power and control signals to an input of a second CRT 20B; an output of the second CRT 20B in turn outputs the video and power and control signals to an input of a third CRT 20C, etc. This process continues until the last CRT in the chain, in this case CRT 20F, is reached. A terminator 30 is typically connected to the output of the last CRT 20F in the chain for purposes of impedance matching.
As is also known, in the airline industry the seating in an aircraft is divided into zones. Typically, these zones are defined as first class, business class and tourist class, or zones one through five and upper-deck. When a daisy chain CRT arrangement of the type described above in connection with FIG. 1 is employed, the CRTs are controlled without respect to the different zones on a particular aircraft. For example, the same movie would be sent to all of the CRTs on a particular aircraft at the same time. As the airlines and their customers desired more sophisticated in-flight entertainment, the CRT monitors became controllable by zones. Such control would typically be accomplished by providing a SCU that is capable of controlling multiple zones and only daisy chaining together the CRTs of a particular zone. As a result, one type of programming could be shown, for example, in first class and a different type of programming shown in tourist class. However, such an added degree of versatility was still not sufficient for the airlines, and this lead to the advent of the smart video distribution unit (SVDU).
SVDU's contain communication bus electronics, e.g., RS-485, and are connected between an SCU and one or more CRTs. SVDU's receive the video and power and control signals form SCU's, interpret these signals, and provide for the control of any single CRT or group of CRTs in response thereto. For example, as shown in FIG. 2, in a given zone of an aircraft there may be three SVDU's 40A-C, each for controlling two CRTs. In this case, SVDU 40A controls CRTs 50A and B, SVDU 40B controls CRTs 50C and D and SVDU 40C controls CRTs 50E and 50F. The SVDUs 40A-C receive information (video and control and power) from the SCU 10 and distribute the information directly to their associated CRTs, i.e., there is no daisy chaining and thus it is not necessary to provide outputs form the CRTs 50A-F. As a result, each group of two CRTs, e.g., 50A and B, can be independently controlled. The SVDUs 40A-C are also arranged to track the status of their respective CRTs. In an even more sophisticated arrangement there may be one SVDU associated with each CRT, providing even more control flexibility.
Typically, SVDUs are mounted between the wall panel and the fuselage of an aircraft. As such, the wall panels of the aircraft must be removed in order to install or service the SVDU's. This is a relatively time consuming process and it would be desirable to carry-out such operations without removing aircraft wall panels.
As the video distribution systems became even more sophisticated, liquid crystal display (LCD) retract devices began to replace conventional CRTs due to their performance and light weight. U.S. Pat. No. 5,096,271 describes such an LCD retract device that is mountable in the passenger service unit of an aircraft: These LCD retract devices are typically coupled with multiple SVDUs (up to one SVDU per LCD) to provide the pinnacle in in-flight entertainment, but at a substantial expense. Furthermore, since these LCD devices have typically been associated with high-end, in-flight entertainment, the daisy-chaining technique of the type described above with respect to CRT monitors has not been employed. As a result, because of their expense, these sophisticated in-flight entertainment systems were in the past found only on wide-body aircraft.
It has presently become desirable to bring more sophisticated entertainment systems typically found only in wide-body aircraft to narrow-body aircraft as a way to generate additional revenue for the airlines while at the same time maintaining versatility of the simpler systems traditionally found in narrow-body aircraft. I would also be desirable to eliminate SVDU's and their complicated installation and maintenance procedures.
Therefore, it is an object of the present invention to provide an interface for an LCD retract device that provides the sophisticated in-flight entertainment typically only found in wide-body aircrafts while at the same time being economical and flexible enough to justify use on smaller aircraft.